The price of a plant reduced by ₹ 6 per week for 7 weeks. By how much did the price of the plant change over the 7 weeks?

During a drought, the water level in a dam fell 3 inches per week for 6 consecutive weeks. What was the change in the water level in the dam at the end of this period?

During the summer, the level of water in a pond decreases by 2 inches every week due to evaporation. What is the change in the level of water over a period of 6 weeks?

The price of a product is related to the number of units available (supply) by the equation Px+3P-16x=234 , where P is the price of the product per unit in Rupees (Rs) and x is the number of units. Find the rate at which the price is changing with respect to time when 90 units are available an the supply is increasing at a rate of units/week .

A small town with a demand of 800 kW of electric power at 220 V is situated 15 km away from an electric plant generating power at 440 V. The resistance of the two wire line carrying power is 0.5 Omega per km. The town gets power from the line through a 4000-220 V step-down transformer at a sub-station in the town. a. Estimate the line power loss in the form of heat. b. How much power must the plant supply assuming there is negligible power less due to leakage? c. Characterise the step up transformer at the plant.

The supply equation is given p(x+2) = 4x + 90 , where p is the price/unit in rupees and x is the no. of units find the rate at which the price is changing with respect to time when 39 units are available and the supply is increasing at the rate of 5 units/week.